Prediction of worsening postoperative renal function in older candidates to elective cardiac surgery: Choosing the best eGFR formula may not be enough.

BACKGROUND: Though renal impairment is highly prevalent in older patients and influence post-operative outcomes in cardiac surgery; its prognostic relevance is debated and not fully assessed by surgical risk scores. OBJECTIVE: We investigated the predictive role of estimated glomerular filtration rate formulas for in-hospital worsening renal function (WRF) after cardiac surgery. METHODS: We prospectively enrolled in single-center cohort study, patients aged ≥ 75 years candidate to elective cardiac surgery. Four creatinine-based equations were used to calculate estimated glomerular filtration rate (eGFR) formulas: Cockroft-Gault, Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology, and Berlin Initiative Study 1 formulas. Each patient underwent geriatric and clinical evaluation before surgery with calculation of the Society of Thoracic Surgeons scores. In-hospital WRF was defined as a composite of an increase in SCr ≥0.5 mg/dl or the occurrence of grade III KDIGO acute kidney injury. The association between each eGFR equation, alone and in models including clinical variables, and WRF was analyzed using logistic regressions and ROC analysis. RESULTS: WRF occurred in 69 patients (19.8%), and the predictors of WRF were previous acute myocardial infarction, hypertension, 4-mt gait speed performance, and preoperative eGFR, irrespective of the equation used. With all equations, inclusion of these additional variables in the logistic regression models improved the prediction of WRF (AUCs 0.798-0.810). CONCLUSIONS: An accurate assessment of renal function and of physical performance should be incorporated into cardiac surgery risk scores to improve prediction of in-hospital WRF and, hence, risk stratification in older adults undergoing elective cardiac surgery.

Age as a Prognostic Factor in Patients with Acute Coronary Syndrome undergoing Urgent/Emergency Cardiac Surgery.

BACKGROUND: Patients presenting with acute coronary syndrome (ACS) who require urgent/emergency coronary artery bypass grafting (CABG) are increasing, as is the complexity of their clinical characteristics, one of which is advanced age. We evaluated the prognostic role of age in patients undergoing urgent/emergency cardiac surgery for ACS. METHODS: From January to December 2013, 452 consecutive patients underwent CABG at our institution. Among these, 213 presented with ACS, were enrolled in the study and divided into tertiles of age: First: 40-65 years old (n=73), Second: 66-74 (n=70), Third: 75-89 (n=70). Patients were followed post-operatively for 30 days. RESULTS: No differences between tertiles were found for baseline clinical and angiographic characteristics. Off-pump interventions were 67.6%. Older patients more frequently required an associate intervention to CABG for a mechanical complication of ACS. Overall 30-day all-cause mortality was 4.7% (n=10); 0.6% (n=1) in patients undergoing isolated CABG (n=168, 78.9%). The STEMI diagnosis was an independent risk factor for 30-day mortality, and age was not. CONCLUSIONS: The 30-day mortality rate of older ACS patients who undergo urgent/emergency CABG is comparable to that of younger ones. Pre-operative risk assessment should rely on evaluation of the clinical complexity of each patient independent of their chronological age, to customise the therapeutic strategy.